Trans-cyclohexane-1,2-diamine is a weak director of absolute helicity in chiral Nickel-Salen complexes

The interconversion between helical diastereomers of nickel-salen-based foldamers can be observed on a NMR time scale. Such complexes provide quantitative information about the propensity of different elements of central chirality to control the absolute sense of folding. trans-Cyclohexane-1,2-diamine-a common component of chiral salen catalysts-is a surprisingly weak director of absolute helicity in nickel-salen foldamers. Implications for asymmetric catalysis are discussed.